As a recording medium for an image-forming apparatus such as a printer, a copier, a facsimile machine and/or the like to form images, a roll-wound recording medium (hereafter called roll paper) in which a recording medium such as paper, film and/or the like is wound around a roll shape exists. The roll paper can be stored without needing to be cut, and thus is widely used when accomplishing large-area image formation without a break, for example in a label printer continuously printing multiple labels or seals.
Accompanying increases in printing quality with digital printing, even with large-area printing using roll paper, quality close to that of printed materials such as flexography, gravure printing, offset printing and/or the like is needed. Consequently, printing with white, transparent and other colors on the roll paper is demanded, in addition to the four colors of YMCK (yellow (Y), magenta (M), cyan (C) and black (K)) that can be used with typical color printers under a four-way tandem method.
Printers corresponding to five-way or more tandem methods are known as a method of adding white and/or other colors to the four colors of YMCK in color printers (for example, see Unexamined Japanese Patent Application Kokai Publication No. 2011-174984).
In addition, a method of creating the K color (black) out of YMCK by superimposing the three colors of YMC (process black) and adding another color in place of the K color is known.